Around 40 people attended the Nitrogen Efficiency Field day at Peter Campbell’s property near Henty on 6 June.

The event featured FertCare registered calibration specialist Russell Nichol, who showed participants how to calibrate their machines to improve the evenness of fertiliser spread.

Over the course of the day, Russell calibrated 3 machines, an Amazone ZAM Ultra Profis, an Amazone Profis 3600L, Amazone ZA-M 1501 3-point linkage and also demonstrated the correct calibration method for a Landaco TS10000 trailing spreader. 

To test the effective spread width and evenness of distribution for each machine, 60 catch trays were lined up across the paddock and collected urea spread from each machine. Fertiliser in the catch trays was weighed and the results graphed using specialised computer software.

On the day, all machines produced uneven ‘pre-calibration’ tests, with ‘Devils Horns’ shaped distribution graphs common – this indicates too little fertiliser was being applied directly behind the spreader.

After the first test, the spreaders had their spinner vane location adjusted, and the test was repeated until the optimal settings were found. Post-calibration testing showed all machines spread at a greater width and a more even distribution than the pre-calibration test.

The quality and composition of urea being used also impacts the spread width.  Having a higher proportion of fine/smaller particles can reduce spread width relative to samples having a higher proportion of large particles (larger granules usually travel further than finer particles). To this end Russell demonstrated the use of a ‘shaker’ or ‘D-indicator’ box to estimate granule sizes for urea. The D Indicator separates granules according to size; the ‘A’ segment collects particles <2mm diameter, 'B' collects particles 2-3.35mm diameter, 'C' collects particles 3.35-4.75mm and 'D'  collects particles > 4.75mm. The ideal indicator result for urea is for the B and C sections to each contain 50% of the product.

Once the fertiliser particle composition is known, the drop point or spinner vanes can be adjusted.  Because each machine is different, Russell advised growers to always refer to the set up and adjustment instructions which can be found in the spreader’s operator manual or labelled on the machine.

A special presentation was also made at lunchtime by Michael Straight, FAR Australia on the results from the Australian Government’s Department of Agriculture and Water Resources project Management strategies for improved productivity and reduced nitrous oxide emissions.